123728705 has 4 divisors (see below), whose sum is σ = 148474452. Its totient is φ = 98982960.

The previous prime is 123728663. The next prime is 123728711. The reversal of 123728705 is 507827321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 507827321 = 1571 ⋅323251.

It can be written as a sum of positive squares in 2 ways, for example, as 20584369 + 103144336 = 4537^2 + 10156^2 .

It is not a de Polignac number, because 123728705 - 2¹² = 123724609 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12372866 + ... + 12372875.

It is an arithmetic number, because the mean of its divisors is an integer number (37118613).

Almost surely, 2^123728705 is an apocalyptic number.

It is an amenable number.

123728705 is a deficient number, since it is larger than the sum of its proper divisors (24745747).

123728705 is an equidigital number, since it uses as much as digits as its factorization.

123728705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24745746.

The product of its (nonzero) digits is 23520, while the sum is 35.

The square root of 123728705 is about 11123.3405503922. The cubic root of 123728705 is about 498.2991608528.

The spelling of 123728705 in words is "one hundred twenty-three million, seven hundred twenty-eight thousand, seven hundred five".